Organometallic chemistry of fluorocarbon acids. Synthesis, structure, and solvolysis of a sulfinate-bridged diruthenium dihydride cluster, [(Ph3P)4Ru2(.mu.-H)2(.mu.-CF3SO2)(CO)2][HC(SO2CF3)2] (original) (raw)
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Organometallics, 1986
Reaction of H2C(S02CF3)2 with (Ph3P),RuH2 in neat arene solvents produces (a-arene)RuH(PPh3).zf-HC(SO2CF&-. The lH NMR spectra of these compounds indicate that substituents on the arene ring stabilize one of several ring rotational conformations. Molecular orbital calculations at the extended Huckel level were utilized to explore the structural distortion of the RuH(PPh&+ units in these compounds as well as the dynamics of rotation about the arene-Ru axis. Computations on (arene)RuH(PH&+ (arene = benzene, aniline, phenylborane) each showed similar distortions in the tripod portion of the molecule which can be traced to more efficient donation of electron density from the hydride to the metal compared to the phosphine ligands. The structure for each of these model compounds was optimized, and barriers to rotation about the arene-Ru bond were computed. Crystal structure determinations on (r-PhCHJ-
Organometallics, 2015
The coordination of the phosphino-alcohol ligands 2-Ph 2 PC 6 H 4 CH(R)OH (R = H, Me) onto an arene-ruthenium(II) fragment gave rise to the formation of complexes of general formula [RuCl 2 {2-Ph 2 PC 6 H 4 CH(R)OH}(η 6 -arene)] (R = H, arene = C 6 H 6 (3a), p-cymene (3b), mesitylene (3c), C 6 Me 6 (3d); R = Me, arene = p-cymene (5b)). In solution, different isomers were observed depending on the solvent polarity. They arise from the different coordination modes adopted by the phosphino-alcohol: (i) the classical κ 1 -P mode through the selective coordination of the phosphorus atom, (ii) the establishment of both Ru−P and Cl····H−O interactions, and (iii) the P,O-chelate formation. Treatment of these species with NaPF 6 led to the selective formation of the corresponding cationic species [RuCl{κ 2 -(P,O)-2-Ph 2 PC 6 H 4 CH(R)OH}(η 6 -arene)][PF 6 ] 6a−d and 7b, respectively. Unexpectedly, under basic conditions these cationic compounds evolved into the neutral α-hydroxy-alkyl derivatives [RuCl{κ 2 -(P,C)-Ph 2 PC 6 H 4 C(R)OH}(η 6 -arene)] through a formal C−H bond activation process.
Inorganic Chemistry, 2008
Arene ruthenium(II) complexes containing bis(pyrazolyl)methane ligands have been prepared by reacting the ligands L′ (L′ in general; specifically L 1 ) H 2 C(pz) 2 , L 2 ) H 2 C(pz Me2 ) 2 , L 3 ) H 2 C(pz 4Me ) 2 , L 4 ) Me 2 C(pz) 2 and L 5 ) Et 2 C(pz) 2 where pz ) pyrazole) with [(arene)RuCl(µ-Cl)] 2 dimers (arene ) p-cymene or benzene). When the reaction was carried out in methanol solution, complexes of the type [(arene)Ru(L′)Cl]Cl were obtained. When L 1 , L 2 , L 3 , and L 5 ligands reacted with excess [(arene)RuCl(µ-Cl)] 2 , [(arene)Ru(L′)Cl][(arene)RuCl 3 ] species have been obtained, whereas by using the L 4 ligand under the same reaction conditions the unexpected [(p-cymene)Ru(pzH) 2 Cl]Cl complex was recovered. The reaction of 1 equiv of [(p-cymene)Ru(L′)Cl]Cl and of [(p-cymene)Ru(pzH) 2 Cl]Cl with 1 equiv of AgX (X ) O 3 SCF 3 or BF 4 ) in methanol afforded the complexes [(p-cymene)Ru(L′)Cl](O 3 SCF 3 ) (L′ ) L 1 or L 2 ) and [(p-cymene)Ru(pzH) 2 Cl]BF 4 , respectively. [(p-cymene)Ru(L 1 )(H 2 O)][PF 6 ] 2 formed when [(p-cymene)Ru(L 1 )Cl]Cl reacts with an excess of AgPF 6 . The solid-state structures of the three complexes, [(p-cymene)Ru{H 2 C(pz) 2 }Cl]Cl, [(p-cymene)Ru{H 2 Cpz 4Me ) 2 }Cl]Cl, and [(pcymene)Ru{H 2 C(pz) 2 }Cl](O 3 SCF 3 ), were determined by X-ray crystallographic studies. The interionic structure of [(pcymene)Ru(L 1 )Cl](O 3 SCF 3 ) and [(p-cymene)Ru(L′)Cl][(p-cymene)RuCl 3 ] (L′ ) L 1 or L 2 ) was investigated through an integrated experimental approach based on NOE and pulsed field gradient spin-echo (PGSE) NMR experiments in CD 2 Cl 2 as a function of the concentration. PGSE NMR measurements indicate the predominance of ion pairs in solution. NOE measurements suggest that (O 3 SCF 3 )approaches the cation orienting itself toward the CH 2 moiety of the L 1 (H 2 C(pz) 2 ) ligand as found in the solid state. Selected Ru species have been preliminarily investigated as catalysts toward styrene oxidation by dihydrogen peroxide, [(p-cymene)Ru(L 1 )(H 2 O)][PF 6 ] 2 being the most active species.
Organometallics, 1994
Reaction of CpRuCl(iPr-DAB) (1) with AgOTf(AgCF3S03) in THF and subsequent addition of L (L = ethene (a), propene (b), cis-2-butene (c), dimethyl maleate (d), dimethyl fumarate (e), fumaronitrile (f), acetylene (i), dimethyl acetylenedicarboxylate (DMAC) Q), CO (11, pyridine (m), triphenylphosphine (n)) led to the ionic complexes [CpRu(iPr-DAB)(L)l[OTfl 2a-f,ij,l-n, respectively. For trans-2-butene (g) and 2-methylpropene (h), no coordination complex was formed. Addition of methyl propiolate (HC4X!(O)OCH3, k) to [CpRu(iPr-DAB)l[OTfl resulted in [ C~R U (~P~-D A B ) (~~-H C~C C ( O ) O C H~) I [ O T~~ (2k) and 21 in a 4:l ratio. An X-ray structure determination on 2b was carried out. Crystal data for 2b: triclinic, space group Pi with a = 9.0649(6) A, b = 9.6151(6) A, c = 13.0099(6) A, a = 94.322(6)", j3 = 104.258(8)", y = 98.977(6)", 2 = 2, final R = 0.033. Surprisingly, the structure shows the propene y2-coordinated to the metal center with the methyl group pointing toward the cyclopentadienyl ring. Nucleophilic attack of OCH3-on [CpRu(iPr-DAB)(q2-dimethyl maleate)l[OTfl (2d) at 20 "C led to two diastereomers of CpRu(iPr-DAB)CH(C(O)OCH3)-CH(OCHd(C(O)OCH3) (3) in a 97:3 ratio. Reaction of [CpRu(iPr-DABXy2-DMAC)1[OTfl (2j) with -0CH3 at 20 "C yielded CpRu(iPr-DAB)OCHs (61, whereas reaction at -40 "C gave 6 (30%) and C~RU(~P~-DAB)C(C(O)OCH~)=C(OCH~)(C(O)OCH~) (4; 70%). Reaction of 2d with NH2iPr and NHiPr2 as the nucleophiles yielded the substitution products [CpRu(iPr-DAB)(NH2iPr)l[OTfl (2p) and [CpRu(iPr-DAB)(NHiPrz)I[OTfl (2q), respectively. Complex 2j reacted with NHziPr to form 2p, whereas 2j was inert to substitution with NHiPr2.
Organometallics, 2002
The reactions of the allenylidene complexes [Cp*Ru{dCdCdC(R)Ph}(dippe)][BPh 4 ] (R) H (1), Ph (2)) with different substrates have been studied, providing a new form of allenylidene-ruthenium reactivity. The observed reactivity pattern depends strongly on the substituents on the γ-carbon. The secondary allenylidene 1 undergoes addition of weakly nucleophilic reagents such as pyrazole, 3,5-dimethylpyrazole, or thiophenol to the CC γ double bond, yielding substituted vinylidene compounds [Cp*Ru{dCdCHCH(L)Ph}(dippe)]-[BPh 4 ] (L) pyrazolyl (3), 3,5-dimethylpyrazolyl (4), phenylsulfanyl (5)). The reaction of 1 with pyrrole or 2-methylfuran to afford analogous complexes [Cp*Ru{dCdCH-CH(L)Ph}-(dippe)][BF 4 ] (L) 2-pyrrolyl (6), 5-methyl-2-furanyl (7)) takes place only in the presence of acid. This suggests that an initial protonation at the-carbon of the allenylidene occurs, enhancing the electrophilic character of the γ-carbon atom. This mechanism involves the formation of dicationic carbyne ruthenium complexes [Cp*Ru{tC-CHdC(R)Ph}(dippe)] 2+ (R) H (8), Ph (9)), which have been isolated and characterized as [B(Ar F) 4 ] (Ar F) 3,5-(CF 3) 2 C 6 H 3) salts, by protonation of the cationic allenylidenes with [H(Et 2 O) 2 ][B(Ar F) 4 ]. The X-ray crystal structure of the carbyne compound 9 is reported. A series of neutral functionalized alkynyl compounds [Cp*Ru{CtCCR(L)Ph}(dippe)] (L) CH 3 COCH 2 , R) H (10), R) Ph (11); L) pyrazolyl, R) H (12); R) Ph (13)) have also been synthesized by regioselective addition of anionic nucleophiles such as potassium acetonate or potassium pyrazolate. The structures of 11 and 13 in the solid state have been determined by X-ray diffraction analysis. Protonation of 10 and 11 with HBF 4 ‚Et 2 O yields the vinylidene compounds [Cp*Ru{dCdCH-CR(CH 2 COCH 3)Ph}(dippe)][BF 4 ] (R) H (14), Ph (15)).
Journal of The American Chemical Society, 1982
Treatment of [RuCl,(ttp)], with excess sodium tetrahydroborate in refluxing tetrahydrofuran produces the yellow, microcrystalline complex RuH(a2-BH4)(ttp), 4, which shows discrete proton N M R signals for the metal hydride, each of the two bridging protons, and the two terminal B-H protons at ambient temperature. A variable-temperature ' H N M R study shows scrambling of the BH4-protons at two different temperatures, and the exchange process can be interpreted as a two-step process. Owing to the presence of both Ru-H and doubly bridged Ru-BH4 linkages in 4, addition of acid or base in the presence of neutral ligands L produces two different series of products, Le., [R~(H)(L)~(ttp)l+, L = CO, CH,CN, and P(OMe),, and RuH,(L)(ttp), L = CO, PPh,, and P(OMe),. In the case of P(OMe),, three different isomers (Le., trans, cis-syn, and cis-anti) are obtained, depending on the sequence of addition of reagents, solvents, and reaction conditions. The cis-syn and cis-anti isomers of [RuH(P(OMe),),(ttp)]+ are the first detected examples where the different structures are due to the fixed stereochemical orientation of the phenyl group on the central phosphorus atom of ttp. When P(OPh), is used as the ligand L, the ortho-metalated product RuH(P(OPh),OPh)(ttp) is obtained instead of the target complex RuHz(P(OPh3)ttp, analogous to the RuH2(P-(OMe),)(ttp) complex. The complexes have been characterized by elemental analyses, conductivity, infrared, proton, and phosphorus-31 N M R spectra, as well as an X-ray structure determination of complex 5d. Complex 4 in the presence of NEt, catalytically hydrogenates 1-octene to octane at a rate comparable to that of RhCI(PPh3),; in the presence of 1 equiv of HBF4.Et,0, 4 catalytically hydrogenates 1-octene at a rate -0.75 that of RhCI(PPh,),.
Journal of the American Chemical Society, 1983
= CH2CH(CH3)2; 6, R = CHzC(CH3)3; 8, R = CH(CH3)2) are synthesized in 49-82% yields by Grignard or alkyllithium attack upon the appropriate [(9-C5H5)Re(NO)(PPh3)(=CHR')]+PF6precursor. The acyl (q-C5H5)Re(NO)(PPh3)-(COCH2C6H5) is prepared from (~-C5H,)Re(NO)(PPh3)(C02CH3) and C6H5CH2MgBr (80%) and is reduced with excess BH3 to alkyl (+25H5)Re(NO)(PPh3)(CHzCHzC6H5) (9, 64%). These alkyls, and previously synthesized (SS,RR)-(v-C5H5)Re(NO)(PPh3)(CH(CH3)C6H5) ((SS,RR)-'I) and (SRJLs)-7, are treated with Ph3C+PF6-at-78 OC, and the regiochemistry and stereochemistry of hydride abstraction is examined. Results obtained by use of appropriately labeled deuterated substrates are as follows: Ph3C+PF6-abstracts the p r e R a-hydride of 2-4 to give alkylidenes sc-[(tpC,H,)Re(NO)(PPh,)(=CHR')]+PF,-(lOk, R' = CH3; Ilk, R' = CHzCH3; 12k, R' = CH2CHzCH2CH3). Upon warming to 10-25 OC, these equilibrate to (90 f 2):(10 f 2) mixtures of ac (lot-12t) and sc Re=C geometric isomers. For 10klot, AH* = 17.4 f 0.5 kcal/mol and AS* =-7.3 f 2.0 eu. Ph3C+PF6-abstracts the P-hydride from 5 to give [(?-C5H5)Re(NO)(PPh3)(HzC=C(CH3)z)]+PF6-(13) but does not appear to abstract hydride from 6. Ph3C+PF6-abstracts @hydrides from (SS,RR)-7 and (SR,RS)-7 to give (RR,SS)-[(~-CSH5)Re(No)(pph3)(Hzc=cHc6H5)]+PF6-((RR,SS)-14) and (RS,SR)-14, respectively. Ph3C+PF6preferentially abstracts /3-hydrides from the pro-R methyl group of 8 to give a (92 f I):(% f 1) mixture of (RR,SS)-[(q-C5H5)Re(NO)(PPh3)(HzC=CHCH3)]+PF6-((RR,SS)-15) and (RS,SR)-15. Ph3C+PF6-abstracts the pro-R a-and both P-hydrides from 9 to give sc-[(?-C5H,)Re(NO)(PPh3)(=CHCH2C6H,)]+PF6-(l a , 63%), (RR$S)-14 (18%), and (RSSR)-14 (18%). Ethylidene 10k is stereospecificially attacked by Li(C2H5),BD, C6H5CH2MgBr, C6H5hfgBr, and PMe3 to give (SR,RS)-2-a-dl, (SS,RR)-(&H5)Re(NO)(PPh3)(CH(CH2C6H5)CH3) ((SS,RR)-17), (SS,RR)-7 and (SS,RR)-[(v-C5H5)Re(NO)(PPh3)(CH(+PMe3)CH3)]PF6-((SS,RR)-18), respectively. Reaction of the 10t/10k equilibrium mixture with Li(C2H5),BD, C6H,CHzMgBr, and PMe, gives corresponding adducts as (10 f 2):(90 2) diastereomer mixtures. The protons of 10t/10k exchange with acetone-d6 without added catalyst.
Polynuclear rhodium(II) compounds with phosphino-phenoxide ligands
Inorganic Chemistry, 1994
The syntheses, spectral properties, and molecular structures of compounds isolated from the reaction of Rhz(02-CCF3)4(acetone)2 with the ether phosphine tris(2,4,6-trimethoxyphenyl)phosphine (TMPP) are described. Two products are formed, the relative yields of which are determined by reaction conditions and stoichiometry. The tetranuclear compound [{Rh2(02CCF3)~[(C6H~(OMe)3)2P(C~H~(OMe)20)]2 (1) is favored under mild conditions with 2 equiv of phosphine ligand whereas the dinuclear product Rh2(02CCF3)2(C6H2(0Me)3)2P{c6H2(oMe)2012 (2) is obtained from further reaction of 1 with TMPP or by reaction of the trifluoroacetate complex with 4 equiv of TMPP. The excess phosphine in these reactions aids in the demethylation of an ortho-methoxy substituent and, if absent, results in a low yield of substitution products. Compound 1 crystallizes as a CHzCl2 solvate in the monoclinic space group P21 n with unit cell dimensions a = 14.718(7) A, b = 24.040(5) A, c = 24.260(6) A, 6 R, = 0.090 with a quality-of-fit = 3.06. An X-ray structure revealed that the molecule exhibits a new binding mode for the TMPP ligand wherein a phenoxide bridge spans two dirhodium units to give a "dimer-of-dimers". The compound dissolves in coordinating solvents with disruption of the intermolecular Rh-phenoxide bonds to give two molecules of the dinuclear species R~~(O~CCFJ)~(TMPP-O)(S) (S = solvent). The tetranuclear structure of 1 is in equilibrium with the dimer form in noncoordinating solvents such as CHCl3, as evidenced by two independent sets of phosphine resonances in the lH NMR and NMR spectra. Compound 2 crystallizes as a CH2Cl2 solvate in the monoclinic space group E 1 / n with unit cell dimensions a = 14.146(4) A, b = 19.56(1) A, c = 23.822(6) A, = 101.90(2)O, V = 6449(4) A3, and Z = 4. Residuals of R = 0.066 and R, = 0.099 were obtained with 805 parameters and a quality-of-fit = 2.94. In 2, each Rh center is bonded to a face-capping TMPP ($-P,O,O) and to cis-trifluoroacetate ligands in the usual bridging mode. The solid-state structure of 2 is preserved in solution, as judged by NMR spectroscopy, which reveals one type of TMPP ligand with magnetically inequivalent arene groups. The results of these studies are in contrast to previous findings for the the corresponding reactions of Rh2(02CCH3)4 with TMPP that produce a dinuclear complex with the ligand arrangement found in 1 but no tetranuclear or bis-substituted products. Details of the syntheses, full characterization of compounds 1 and 2, and a comparison of this work to related chemistry are described.
Inorganic Chemistry, 2004
A series of new Ru(II) arene phosphine complexes derived from Binap have been prepared. Specifically, reaction of Ru(OAc)(2)(Binap) with 3,5-(CF(3))(2)C(6)H(3))(4)B (BArF).H(OEt(2))(2), is shown to afford new mono- and dinuclear Ru(II) hydroxyphosphine pi-arene complexes via a series of P-C bond cleavage reactions. The dinuclear Ru(II) pi-arene complexes contain bridging P(O)(OH)(2) ligands. Crystal structures of five new complexes are reported and suggest an eta(4)-arene rather than an eta(6)-arene coordination mode. However, in solution, their (13)C NMR data are more consistent with a strongly distorted eta(6)-coordination mode. PGSE (1)H and (19)F diffusion measurements on the dinuclear complexes suggest hydrogen bonding of the triflate anion and ion-pairing of the BArF(-) anion.